I don't think the plastic backs are meant to show. If you have small earlobes, swap the backs provided for some other neater butterfly backs . Most jewellry shops have several types or Claire's stock them as has been said. Great earrings btw!

I have a pair like that and if I push the butterfly in the right place, the plastic disc pops off! They actually sit better on the lobe with the disc on so I leave them, but I just thought I'd let you know that you can take them off if you really don't like them!